Trigger mechanism for automatic small firearms



W. C. L. HAUBROE TRIGGER MECHANISM FOR AUTOMATIC SMALL FIREARMS Filed Sept. 5, 1924 2 Shasta-Sheet 1 Aug. 17 1926. 59,177

' w. c. L. HAUBROE TRIGGER HECHANISM FOR AUTOMATIC SMALL FIREARMS Filed Sept. 5, 1924 2 Sheets-Sheet 2 Patented Aug. 17,

UNITEDF'STATES PATENT OFFICE.

wnmmn CHRISTIAN mssnn momma, or comment, unman TRIGGER IEGEANISH FOR AUTOMATIC FIREARMS.

Application filed September 3, 1924, Serial fie. 785,545, and in France September M, .1928.

present invention is arranged in such a manner That a cartridge inserted all the way into the chamber will always be fired when the barrel and the breech block have been moved forward into their foremost position That the barrel and the breech block will always remain in the withdrawn position, when the trigger is released,

That the barrel and the breech block, when the gun is secured, while these parts are in their rearmost position, cannot be moved forward into their foremost position, whereby the danger is removed that a cartridge may be moved into the chamber and, ifthe latter is sufliciently hot, may be fired by self-ignition,

That the barrel and the breech block are prevented from being moved home into their foremost position, when by a wrong operation the safety device is turned into an intermediate position. v

This position is selected in such a manner that the breech may be closed over the cartridge which is introduced into the chamber after the error of operation has been remedied. Before firing is resumed, the car-.

tridge is ejected from the chamber by a loading manipulation, and the safety device is then turned into free position, whereafter the-gun is once more ready to be fired.

The following description will explain how these advantages are attained.

The invention is illustrated on the draw- Figs. 1 and 2 showing sections along the lines 'II and 11-11, respectively, in Fig. 3, a

Fig. 3 the trigger mechanism in top view,

Fig. 4 a sectlon along the line IVIV of Fig. 3,

Figs. 5 and 6 showing sections corresponding to those shown in Figs. 1 and 2, but with theparts in a difierent position,

Figs. 7, 8 and 9, on a larger scale, the trigger mechanism proper in side elevation,

front elevation and in top View, respectively, v

Fig. 10 the trigger mechanism in side elevation with the parts in another position than the one shown in Fig. 7 and Figs. 11 and 12 some details in perspective view. I a

1 is the lock'frame and '2 a bolt journalled in the same, the recoil lever 3 being rigidly attached to the said bolt, while the percussion lever 4. is free to rotate about the bolt. 5 is the recoil spring and 6 the percussion spring, co-operating with the recoil lever 3 and the percussion lever 4, respectively, the

said springs becoming tightened, when the levers 3 and 4 by the return motion of the barrel and thebreech block are turned from the position shown in Figs. 5 and 6 into those shown in'Figs. 1 and 2. I

The trig er is pivoted about a bolt 9 journalled in t e trigger plate 8, and is shaped as a two-armed lever, one arm 7 of which forms the trigger proper, while its other forwardly directed arm 10 is actuated by a helical spring 11, and has a fixed stopping hook 12. On the bolt 9 is further hung the sear 13, which is a single-armed lever rovided alongside the trigger and actuate by a helical spring 14. The scar has a fixed stopping hook 15 and, on the side facing the trigger arm 10, a projection 16, Figs. 8, 9 and 11, which fits into a notch 17, Figs. 8 and 12 in the upper face of the trigger arm 10. The trigger arm 10 is fitted, at its front end, with a beak 24 and the sear similarly with a beak 25. The latter is, as it appears from Figs. 7 and 9, slightly longer than the beak 24.

On the hub of the recoil lever 3 there is provided a lug 18 above the trigger arm 10 and also above the projection 16 on the side of the sear. The hub of the recoil lever is further fitted with a stop 19 adapted to cooperate with the stopping hook 12 of the trigger arm 10, and the hub of the percussion lever is fitted with a stop 23 adapted to co-operate with the stopping hook 15 of the sear 13.

20 is a tappet provided in the lock frame and adapted to limit the forward motion of the percussion lever, and the percussion lever rests against this tappet, when the lock mechanism is to be put to ether after having been taken apart. 21 is the safety bolt with a projecting lug 22.

By the recoil of the barrel and the breech block the recoil lever 3 and the percussion lever 4 are returned in known manner the positions shown in Figs. 5 and 6 mto those shown in Figs..1 and 2. When the trigger is free, its stopping hook 12 w1ll catch the stop 19 of the recoil lever, whereby the. recoil lever is arrested, so that the recoil spring 5 cannot then move the barrel and the breech block forward. At the same time the percussionlever is arrested by the stopping hook 15 of the sear 13 engaglng the stop 23 of the percussion lever.

When now the grip 7 of the tngger 1s pulled-back, then the stopping hook 12 of the trigger will be withdrawn from the sto 19 on the recoil lever, which is hereby turne forward 'by the recoil sprin 5, and moves the breech block and the arrel forward into their forward position. During this rotation of the recoil lever, the projection 18 on the hub of the recoil lever will exert a downward pressure on the projection 16 on the sear 13, whereby the atter is forced downward alongside the forwardly directed arm 10 of the trigger, whereby the stopping hook 15 of the sear is removed from the sto 23 of the ercussion lever, so that the sai lever may be moved forward by the percussion spring 6 for firing the charge. By the recoil the barrel and the breech block are again withdrawn, whereby the recoil lever and the percussion lever are turned from the positions shown in Figs. 5 and 6 into those shown in Figs. 1 and 2. During firing the trigger grip 7 is constantly maintained in the withdrawn position, so that the trigger lever 10 is moved down so far that its stopping hook 12 cannot catch the stop 19 of the recoil lever and, consequently, the recoil lever will not be arrested. By the rearward rotation of the recoil lever the lug on this lever releases the sear 13, whereby the latter while actuated by the spring 14 is moved upward, so that the stopping hook 15, when the percussion lever is turned into the osition shown in Fig. 2 enters up behin the stop 23 of the said lever and, thereby maintains the percussion lever in the arrested position. The recoil lever as mentioned above being not arrested during the return motion, it will immediatelyth'ereafter be turned forward again by action of the recoil spring. During the last portion of this forward rotation the'projection '18 of the recoil lever releases again the sear 13, so that the percussion lever, after the forward motion as been finished, is again turned forward by the percussion lever, and fires a new shot. The same operation is repeated during the subsequent recoils and forward mo- .tions, as long as the trigger grip 7 is maintained in its rear osition. If the triggpr gr1p is released, when firing is to cease, t on the trigger spring 11 will 'tend to force the'trigg'er' arm 10 upward.

wearer 1f the trigger gri happens to be released during the forwar motion, then the projection 18 of the recoil lever will depress the sear at the end of the forward motion, and the cartridge which is inserted in the chamher will therefore be fired in normal manner. During the recoil, on the contrary, the trigger lever 10 is released by the rotation of the recoil lever into the position shown in Fig. 1, and the stopping hook 12 of the trigger lever 10 will therefore enter into engagement with'the stop 19 of the recoil lever, when the return motion is finished, whereby the recoil lever is arrested in such a manner that the forward motion will be prevented. The percussion lever is arrested in the above described manner by the stopping hook 15 of the sear. 1f the trigger grip is released during the recoil, then the stopping hook 23 of the trigger arm lfi will arrest the recoil lever, in the same manner asdescribed, above after the recoil is finished.

From the above it appears that a cartridge 1 which when firing is stopped has been inserted into the chamber or is inserted therein will always be fired and that the mechanism, after the cartridge has been fired, is locked in the withdrawn osition, so that no fresh cartridge can be inserted into the chamber before the mechanism is again released by the tri ger grip being pulled back. Hereby the anger of chance shots in consequence of the weapon being loaded during its removal from one place to another will be avoided. 4 i

As a security against the weapon being loaded and fired by accidental pull on the trigger grip, the safety bolt 21 is provided with the lug 22, which when the bolt is rotated will be swung in below the beaks 24 and 25 of the trigger lever and the sear, re-.

When now in order to remove the cause of this failure of the mechanism the trigger grip is released, the safety bolt 21 should first be turned. The projection 22 of this bolt will then slide below the front portion of the beak 25 of the sear 13, until the said projection reaches the front end of the beak 24 of the trigger arm 10. The projection 22 cannot enter below this beak, as the trigger arm 10 is maintained de ressed b the hub of. the recoil lever, see ig. 5. en the cause of the failure of the mechanism has been removed and the forward motion stopping hook 12 of the trigger lever 10 en'- gegmg the rear face of the stop 19 of the recoil lever. The projection 22 of the safety bolt is now turned away from the beak 25 of the scar, and firing may then be continued by a pull on the trigger grip 7. By

the above described locking arrangement, untimely firing of the cartridge about to be moved forward, when the failure of the mechanism occurred will be prevented.

The above described trigger mechanism odors not only security against the weapon being loaded when firing stops, but an essential advantage of the mechanism is that it consists of extremely few parts co-operating with each other and with the recoil lever and the ercussion lever in a most simple and relia le manner. In consequence of the simple construction the arts may be made very solid, because owing to their small number there will be more room in the lock frame than in case of the heretofore used more complicated mechanisms, so ililflt the mechanism becomes far more dura- Having thus described my invention, what I claim is 1. An automatic firearm comprising, in combination, a reciprocable barrel and breech block, a sprin' -actuated recoil lever for impart-in forwar motion to said barrel and breech b ock, a sprin -actuated percussion lever, means actuated the recoil of the barrel and breech block for setting both.

of said levers, a pivoted trigger for retainin the recoil .lever in set position, a pivots sear for retaining the percussion lever in set position, a trigger grip for manually rocking said trigger on its pivot thereby to release said recoil lever, said trigger having a depression and the sear having a pro'ectmg portion adapted to be seated in said de ression, a" projection carried by the recoil ever and adapted to enga e said projecting'portion thereby to rock t e sear on its pivot and release the percussion lever during the forward motion of the recoil lever, the organization being such that when the trigger grip is held so as to maintain the trigger in its rocked osition the recoil and percussion levers Wlll be automatically reciprocated and if said gri is released during the forward motion sai reciprocating motion will continue until the levers arrive at the limit of their recoil motion, said trigger and sear being actuated during said recoil motion to lock said levers.

2. An automatic firearm comprising, in combination, a reciprocable barrel and breech block, a sprin -actuated recoil lever for impartin forwar motion to said barrel and breech fiock, a sprin -actuatedpercussion lever, means actuated by the recoil of the barrel and breech block for setting both of said levers, a pivoted trigger for retaining the recoil lever in set position a pivoted sear for retaining the rcussion ever in set sition, a trigger grip for manually rocking said trigger on its pivot thereby to release said recoil lever, said trigger having a depression and the sear having a pro'ecting portion adapted to be seated in said epres-' sion, a projection carried by the recoil lever and adapted to engage said projecting portion thereby to rock the scar on its pivot and release the percussion lever during the forward motion of the recoil'lever, the organ ization being such that when the trigger grip is held so as to maintain the trigger in its rocked position the recoil and percussion levers will be automatically reciprocated and if said grip is released during the forward motion said reciprocating motion will continue until the levers arrive at the limit oi'their recoil motion, said trigger and sear being actuated during said recoil motion to lock said levers, said tri ger and sear each having at its forward en a projecting portion, and a rotatable bolt having a projection adapted to ngage the projections of the trigger and sea -'thereby to prevent actuation of the trigger grip.

3. An automatic firearm comprising, in combination, a reciprocable barrel and breech block, asprin -actuated recoil lever for imparting forvvar motion to said barrel and breech block, a spring-actuated percussion lever, means actuated by the recoil of the barrel and breech block for setting both of said levers, a pivoted trigger for retaining 'the recoil lever in set position, a pivoted sear for retaining the percussion lever in set position, a trigger grip for manually rocking said trigger on its pivot thereby to release said recoil lever,

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said trigger having a depression and the sear having a projecting portion adapted to be seated in said depression, a projection carried by the recoil lever and motion snid reciprocating motion contrigger and sear thereby to prevent actuation tmue until the levers arrive at the limit of of the trigger grip, said projections being 1 their recoil motion, said trigger and sear so disposed that said bolt projection may being actuated during said recoil motion to engage the sear projection independently of lock said levers, said trigger and seer each th t i ger projection.

having at its forward end a projecting por- I testimony whereof I have signed my tion, and a rotable bolt havmg a. promotion name t thi specification, v ndcpted to engage the projections of the worm cemsrmn LASSEN MAUWUE. 

